a) x . 17,7 - 7,7 . x = 177
\(\Rightarrow\) x . ( 17,7 - 7,7 ) = 177
\(\Rightarrow\) x . 10 = 177
x = 177 : 10
x = 17,7
b) 9 . ( 12 - 2 . x ) = 54
\(\Rightarrow\) 9 . ( 10 . x ) = 54
10 . x = 54 : 9
10 . x = 6
x = 6 . 10
x = 60
\(x.17,7-7,7.x=177\)
\(\Rightarrow x.\left(17,7-7,7\right)=177\)
\(\Rightarrow x.10=177\)
\(\Rightarrow x=177:10=17,7\)
\(9\left(12-2x\right)=54\)
\(\Rightarrow12-2x=54:9=6\)
\(\Rightarrow2x=12-6=6\)
\(\Rightarrow x=6:2=3\)
